We will have the following:
a. We can see that the angle opposite to x is 45° and the angle opposite to 10 is also 45°; from theorems [Congruent angles that oppose sides in a triangle have that those sides are also congruent]; so:
x = 10.
Now, we determine y using the law of sines:
![(y)/(sin(90))=(10)/(sin(45))\Rightarrow y=10√(2)](https://img.qammunity.org/2023/formulas/mathematics/college/4sqk1d68l1trk15b2ni3vgkeua3whgm40m.png)
Now, we determine the height of the triangle:
![\begin{gathered} 10^2=(5√(2))^2+h^2\Rightarrow h^2=100-50 \\ \\ \Rightarrow h=5√(2) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/5nizeczmpb7iytwiv4cndy1p6o35k449ac.png)
So, the perimeter is:
![P=10+10+10√(2)\Rightarrow P=20+10√(2)](https://img.qammunity.org/2023/formulas/mathematics/college/8zo5wajxccy5xeuk050vlm3a2a6xd7adte.png)
The area is:
![A=((10√(2))(5√(2)))/(2)\Rightarrow A=50](https://img.qammunity.org/2023/formulas/mathematics/college/fpvcdjuiae8s5zg66la2578yup3cziwbjb.png)
b. Same as in the previous triangle we will determine x and y:
x = 15
![(y)/(sin(60))=(15)/(sin(60))\Rightarrow y=15](https://img.qammunity.org/2023/formulas/mathematics/college/4ybo2i706g52v6cjeqskwqy2fysu6w03p3.png)
Now, we determine the height of the triangle:
![h=\sqrt{(15)^2-((15)/(2))^2}\Rightarrow h=(15√(3))/(2)](https://img.qammunity.org/2023/formulas/mathematics/college/norjlqejsnfjj26eoc1tpx2jsn0f92djtj.png)
So, the perimeter is:
![P=15+15+15\Rightarrow P=45](https://img.qammunity.org/2023/formulas/mathematics/college/1xtffhj5xx0vnzodw8hapzdytyq1o5g7nv.png)
The area is:
![A=((15)((15√(3))/(2)))/(2)\Rightarrow A=(225√(3))/(4)](https://img.qammunity.org/2023/formulas/mathematics/college/nxxa07hdltdguprnfs1v2cfjy9diox94ys.png)